/*java jdk 1.7+
# -*- coding: utf-8 -
'''
Created on 2020年05月10日
@author: zxyong 13738196011
'''*/

package com.zxy.common;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class WeixinCheckUtil
{
	// 与接口配置信息中的Token要一致
	private static String token = "1qaz2wsxADMIN";

	/**
	 * 验证签名
	 * 
	 * @param signature
	 * @param timestamp
	 * @param nonce
	 * @return
	 */
	public static boolean checkSignature(String signature, String timestamp, String nonce) throws Exception
	{
		String[] arr = new String[]
		{ token, timestamp, nonce };
		// 将token、timestamp、nonce三个参数进行字典序排序
		// Arrays.sort(arr);
		sort(arr);
		StringBuilder content = new StringBuilder();
		for(int i = 0;i < arr.length;i++)
		{
			content.append(arr[i]);
		}
		MessageDigest md = null;
		String tmpStr = null;

		md = MessageDigest.getInstance("SHA-1");
		// 将三个参数字符串拼接成一个字符串进行sha1加密
		byte[] digest = md.digest(content.toString().getBytes());
		tmpStr = byteToStr(digest);
		content = null;
		// 将sha1加密后的字符串可与signature对比，标识该请求来源于微信

		return !java.util.Objects.equals(tmpStr,null) ? tmpStr.equals(signature.toUpperCase()) : false;
	}

	/**
	 * 将字节数组转换为十六进制字符串
	 * 
	 * @param byteArray
	 * @return
	 */
	private static String byteToStr(byte[] byteArray)
	{
		String strDigest = "";
		for(int i = 0;i < byteArray.length;i++)
		{
			strDigest += byteToHexStr(byteArray[i]);
		}
		return strDigest;
	}

	/**
	 * 将字节转换为十六进制字符串
	 * 
	 * @param mByte
	 * @return
	 */
	private static String byteToHexStr(byte mByte)
	{
		char[] Digit =
		{ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D',
				'E', 'F' };
		char[] tempArr = new char[2];
		tempArr[0] = Digit[(mByte >>> 4) & 0X0F];
		tempArr[1] = Digit[mByte & 0X0F];
		String s = new String(tempArr);
		return s;
	}

	public static void sort(String a[])
	{
		for(int i = 0;i < a.length - 1;i++)
		{
			for(int j = i + 1;j < a.length;j++)
			{
				if(a[j].compareTo(a[i]) < 0)
				{
					String temp = a[i];
					a[i] = a[j];
					a[j] = temp;
				}
			}
		}
	}
}